Transcript Chemistry Lesson 40 Organic Chemistry

Lesson 40 Organic Chemistry
Objectives:
The student will explain why carbon chemistry is
classified separately from inorganic chemistry.
The student will list the first ten straight chain
alkanes.
The student will list the six common organic
functional groups.
The student will classify compounds, given as
names or structures, as containing one of the six
common organic functional groups.
PA Science and Technology Standards: 3.4.10.A; 3.4.12.A;
3.1.10.C
I. Carbon and bonding
a.
Carbon often forms bonds with
four other atoms.
b.
These reflect a tetrahedral type of
geometry
c.
They often form long chains of
atoms also
II. Carbon can form covalent networks
a.
b.
c.
d.
Carbon forms two common compounds, graphite and
diamond
These two substances have properties both similar to
covalent compounds and unlike most covalent
compounds.
Both are considered network solids.
i. In diamonds, the atoms are arranged in a network
where each carbon is bonded to four other carbons.
ii. In graphite, the carbons are bonded to three other
carbons in layers, and then London forces hold the
layers together.
Their properties are very different, though
i. Diamonds are one of the hardest substances we
know of
ii. Graphite crumbles easily and is a good lubricant
III. Organic Compounds are important to life
a.
All major molecules in living things,
such as proteins, carbohydrates, lipids,
and nucleic acids, contain carbon
backbones.
b.
Organic compound – a compound
containing carbon
c.
More than 6,000,000 organic compounds
have been identified and named.
IV.
Hydrocarbons are the simplest organic compounds
a. Hydrocarbons are composed of only carbon and hydrogen.
b. The simplest hydrocarbons are called alkanes, and their
names end in –ane. All of these mentioned are straight
chains.
c. The general formula for these is CnH2n+2
i.
methane – CH4
ii.
ethane – C2H6
iii.
propane – C3H8
iv.
butane – C4H10
v.
pentane – C5H12
vi.
hexane – C6H14
vii.
heptane – C7H16
viii.
octane – C8H18
ix.
nonane – C9H20
x.
decane – C10H22
d. You need to know these for the test!
e.
Examples – stick figure drawings:
V.
Functional groups determine properties of organic
molecules.
a.
b.
c.
d.
Most organic molecules are bonded to
nitrogen or oxygen molecules, along with the
carbons and hydrogens.
Functional group – group of atoms that
determines an organic molecule’s chemical
properties.
The compounds in each class have similar
chemical properties because of the
functional groups that they possess.
The name also identifies the functional
group
e.
Functional groups: (name, group, ending for
compound names)
i. Alcohol – C-OH – (-ol)
ii.
Ether – C-O-C – (ether)
iii.
Aldehyde – CH=O – (-al)
iv.
Organic acid – COOH – (-oic acid or –ate for
ionized form)
v.
Ketone – C=O – (-one)
vi.
Amine – Contains a C-N bond – (-amine,
amino-, -ine, or azo-)
vii.
Ester – COO in the middle of a
molecule – (-oate on the second name)
viii.
Aromatic – Contains a benzene ring –
these can be a completely separate class
of compounds, or the rings can be used
as functional groups in a compound.
Structure of Benzene
f. Know these for the test!
g. Some compounds have more than one
functional group – such as amino acids,
which contain an amine (C-N) group
and an organic acid (COOH) group.
h. Naming organic compounds with
functional groups involves using the
alkane name, and adding the
prefix/suffix for the functional group.
VI. Carbon atoms can also form ring structures
a.
Examples:
b.
c.
A special kind of ring structure is the
benzene ring. We have seen this above.
Remember that benzene also contains
several resonance structures.
VII.
Organic compounds are often
abbreviated
a.
In organic structural
formulas, carbons and hydrogens
are not represented.
b. This simplifies the drawing,
as well as making it easier to find
functional groups.
c.
Example of different types of
abbreviated drawings.